Geographic Range

European shags are found throughout western Europe, from Iceland, the British Isles, Portugal, Gibraltar, and northern Africa east to Greece and north into the Ukraine and as far north as Norway. There are 3 recognized subspecies: P. a. aristotelis occurs from Iceland to Scandinavia and south to the Iberian Peninsula, P. a. desmarestii occurs in the central Mediterranean to the Black Sea, and P. a. riggenbachi occurs along the coast of North Africa. (BirdLife International 2008, 2008; del Hoyo, et al., 1992)

Habitat

European shags are found along rocky, marine coastlines and islands and are never found very far from land or very far inland. Preferred foraging grounds are in clear, protected waters over sand or rocky substrates, such as in bays or coastal channels. They avoid fresh, brackish, or muddy water. (BirdLife International 2008, 2008; del Hoyo, et al., 1992)

Physical Description

European shags are from 65 to 80 cm in length and 90 to 105 cm in wingspan. They average 2 kg in mass. They have black plumage overall with greenish iridescent hues. They have black feet, legs, and bill, with bright yellow skin at the base of the bill and bright turquoise eyes. They have a small, single, black crest that develops in the breeding season, when they also develop their most intense green hues to the plumage. Non-breeding adults have duller plumage with a pale chin, mottled plumage on the throat, and the bill becomes yellowish. Juveniles are uniformly brown and have pale areas on the head and underparts. They are similar in appearance to great cormorants (Phalacrocorax carbo), but are overall smaller. (Arkive.org, 2009; del Hoyo, et al., 1992)

Reproduction

European shags build nests of sticks, seaweed, and other marine debris on rocky ledges, cliffs, or stacks. Nests have been found from just above the high water level to 100 m above the sea. Nesting areas host large concentrations of these birds, who nest in close proximity. Nests are said to have an intense, unpleasant smell, especially as the seaweed rots. Larger nests have higher success rates than smaller nests and nests on narrow cliffs are less successful than those in other areas. Breeding season varies regionally, with southern populations (Tunisia) breeding from November to February, Black Sea populations breeding from January to March, and northern Atlantic populations breeding from March through June. Females lay from 1 to 6 eggs (usually 3), usually begin incubation after laying the 2nd egg, and incubate them for 30 to 31 days. Hatchling European shags fledge at about 53 days, remain in the nest for 8 weeks after hatching, and are cared for by their parents for 15 to 50 days after they fledge. Within 30 days of hatching males are generally larger than females and the hatchling from the last egg laid is generally smaller. Females may breed as early as their 2nd year. (Arkive.org, 2009; BirdLife International 2008, 2008; del Hoyo, et al., 1992; Snow, 2008)

Breeding season varies with region, occuring between November and June throughout their range.

Range eggs per season

1 to 6

Average eggs per season

3

Range time to hatching

30 to 31 days

Average fledging age

53 days

Range time to independence

68 to 103 days

Range age at sexual or reproductive maturity (female)

2 (low) years

European shag hatchlings are naked at hatching and develop brown down. They fledge at about 53 days old. Both adults protect and provide for their young, incubating them between their feet and breast and alternating duties. They continue to provide food for another 15 to 50 days after the young have fledged. At one site hatching success was from 69 to 73% and fledging success was from 67 to 95%. Most mortality of young is associated with food shortages. (del Hoyo, et al., 1992; Snow, 2008)

Lifespan/Longevity

Maximum lifespan is not reported for European shags, but studies demonstrate that most mortality occurs in the first year of life as a direct result of lower foraging efficiency. Other significant sources of mortality are accidental and intentional deaths through entanglement in fishing gear and persecution by humans. (del Hoyo, et al., 1992)

Behavior

European shag populations do not migrate. Juveniles may disperse short distances after independence, up to 200 km, but adults tend to stay in the same general area for the remainder of their lives, only moving up to 100 km. Occasionally, strong storms blow European shags long distances inland, where they become stranded and often die. Birds generally return to their natal colonies to breed. They are social, breeding in large, dense colonies and foraging either alone or in large flocks during the day. (Arkive.org, 2009; BirdLife International 2008, 2008)

Economic Importance for Humans: Positive

Economic Importance for Humans: Negative

European shags are persecuted because of the perception that they interfere with commercial or subsistence fishing, although they eat mainly small fish so are unlikely to compete directly with humans for prey. They may interfere at hatcheries. (BirdLife International 2008, 2008)

Conservation Status

European shags have a large range and population estimates are approximately 260,000 to 290,000 individuals. Large population declines have not been documented and they are considered "least concern" by the IUCN. They are often entangled and killed in fishing gear and nets or are intentionally killed by fishermen. They are vulnerable to the impacts of coastal pollution, such as oil spills. (BirdLife International 2008, 2008)

Other Comments

European shags are sometimes placed in the genus Stictocarbo. They are also known as common shags, green shags, or green cormorants. In French they are known as Cormoran huppé, in German they are called Krähenscharbe, and in Spanish they are called Cormorán Moñudo. The name "shag" comes from the Old Norse word "skegg" for "beard," possibly referring to the crest. (Arkive.org, 2009; del Hoyo, et al., 1992)

Contributors

Tanya Dewey (author), Animal Diversity Web.

Glossary

Palearctic

living in the northern part of the Old World. In otherwords, Europe and Asia and northern Africa.

acoustic

uses sound to communicate

altricial

young are born in a relatively underdeveloped state; they are unable to feed or care for themselves or locomote independently for a period of time after birth/hatching. In birds, naked and helpless after hatching.

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

carnivore

an animal that mainly eats meat

chemical

uses smells or other chemicals to communicate

coastal

the nearshore aquatic habitats near a coast, or shoreline.

colonial

used loosely to describe any group of organisms living together or in close proximity to each other - for example nesting shorebirds that live in large colonies. More specifically refers to a group of organisms in which members act as specialized subunits (a continuous, modular society) - as in clonal organisms.

diurnal

active during the day, 2. lasting for one day.

endothermic

animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.

food

A substance that provides both nutrients and energy to a living thing.

iteroparous

offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).

monogamous

Having one mate at a time.

motile

having the capacity to move from one place to another.

natatorial

specialized for swimming

native range

the area in which the animal is naturally found, the region in which it is endemic.

oviparous

reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.

piscivore

an animal that mainly eats fish

saltwater or marine

mainly lives in oceans, seas, or other bodies of salt water.

seasonal breeding

breeding is confined to a particular season

sedentary

remains in the same area

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

social

associates with others of its species; forms social groups.

tactile

uses touch to communicate

temperate

that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).

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The Animal Diversity Web is an educational resource written largely by and for college students. ADW doesn't cover all species in the world, nor does it include all the latest scientific information about organisms we describe. Though we edit our accounts for accuracy, we cannot guarantee all information in those accounts. While ADW staff and contributors provide references to books and websites that we believe are reputable, we cannot necessarily endorse the contents of references beyond our control.

This material is based upon work supported by the
National Science Foundation
Grants DRL 0089283, DRL 0628151, DUE 0633095, DRL 0918590, and DUE 1122742. Additional support has come from the Marisla Foundation, UM College of Literature, Science, and the Arts, Museum of Zoology, and Information and Technology Services.